Shirahata Spring
Analysis UnverifiedShirahatage Genzen, located in Kusatsu Onsen and adjacent to Yubatake (Kusatsu's central hot-water field), is said to have been discovered by Minamoto no Yoritomo. Historically, it served as the stage for 'Jikan-yu' (timed bathing), supporting balneotherapy culture, and is truly considered the soul of Kusatsu. Its distinctive aroma and powerful waters, which feel as though they firm the skin, seem to awaken the mind and body from within. Surrendering to its embrace offers a pure moment to shed daily clamor and rediscover one's true self. This spring is a sanctuary for those seeking a fresh start and rejuvenation.
The bar length shows how abundant each component is compared to thresholds that make it "distinctive" (therapeutic spring standards, beauty spring criteria, etc.).
Strong astringent action that tightens skin. A key component of acidic springs, suited to oily or acne-prone skin.
The source of the distinctive sulfur smell. Dilates blood vessels via skin and inhalation to strongly boost circulation.
Mild antibacterial action keeps the skin clean. Trace transdermal absorption supports tooth and bone health.
A natural moisturizer also used in skincare lotions. Forms a thin veil on the skin to reduce moisture loss after bathing.
A trace component with gentle antibacterial and anti-inflammatory action.
Scores are calculated from mineral analysis data based on the Mineral Spring Analysis Guidelines (Ministry of Environment, Japan). They are unrelated to facility atmosphere or service quality.
▸Note
The temperature, pH and component values shown here are based on the hot spring analysis (source). Actual values in the bath may differ depending on heating, dilution, recycling and filtration. Please check current usage status at the facility.
Given its intense acidity (pH 2.05), begin with short immersions of 3–5 minutes to gauge your skin's response, gradually extending to 15–20 minutes. After bathing, resist the urge to rinse immediately; instead, gently pat dry with a towel and rest warmly to allow mineral compounds to linger and penetrate deeper. Those with particularly sensitive skin should rinse promptly if irritation arises.
With a spring temperature of 51.9℃ and a powerful pH of 2.05, this sulfur-rich acidic spring delivers 685.5 mg/kg sulfate ions and 328.1 mg/kg chloride ions, alongside 6.4 mg/kg free hydrogen sulfide—a potent formula for treating dermatological conditions. The synergy of intense acidity and sulfur compounds bactericizes and softens skin layers, making it especially cherished by those battling atopic dermatitis, psoriasis, and chronic eczema. Its scope of benefit extends to chronic pain (joint rheumatism, lower back pain, neuralgia), autonomic nervous system imbalance, and stress-induced sleep disorders.
Those with hypersensitive skin or mucous membranes, elderly individuals with dry skin conditions, and those with serious cardiac, pulmonary, or renal disease should refrain from bathing. Its strong acidity demands that sensitive-skinned bathers rinse thoroughly with warm water post-immersion. Bathing is contraindicated during active hemorrhage or fever.
※ See the analysis data below for detailed contraindications
ANALYSIS DATAView all analysis fields ▼
Source Info
- Source name
- Shirahata Spring
- Spring type
- Acidic sulfurous aluminum sulfate chloride spring (hydrogen sulfide type) (hypotonic acidic hot spring)
- Source temperature
- 51.9℃
- pH
- 2
- Flow type
- Natural spring
- Osmotic pressure
- Hypotonic
Analysis Document
- Analysis date
- 2023-08-04
- Analyst organization
- 一般社団法人 群馬県薬剤師会（環境衛生試験センター）
- Registration No.
- 群馬薬第2号
Cations
- Hydrogen ion H⁺
- 9.3 mg/kg
- Sodium ion Na⁺
- 67.0 mg/kg
- Potassium ion K⁺
- 26.3 mg/kg
- Ammonium ion NH₄⁺
- 0.30 mg/kg
- Magnesium ion Mg²⁺
- 41.2 mg/kg
- Calcium ion Ca²⁺
- 78.0 mg/kg
- Aluminum ion Al³⁺
- 47.1 mg/kg
- Manganese ion Mn²⁺
- 1.9 mg/kg
- Iron(II) ion Fe²⁺
- 18.5 mg/kg
- Total cations
- 0.29 mg/kg
Anions
- Fluoride ion F⁻
- 10.0 mg/kg
- Chloride ion Cl⁻
- 328 mg/kg
- Sulfate ion SO₄²⁻
- 686 mg/kg
- Hydrogen sulfate HSO₄⁻
- 216 mg/kg
- Total anions
- 1.2 mg/kg
Undissociated Components
- Metasilicic acid H₂SiO₃
- 241 mg/kg
- Metaboric acid HBO₂
- 9.6 mg/kg
- Total undissociated
- 0.26 mg/kg
Dissolved Gas
- Free carbon dioxide CO₂
- 29.3 mg/kg
- Free hydrogen sulfide H₂S
- 6.4 mg/kg
- Total dissolved gas
- 0.04 mg/kg
Totals
- Total dissolved substances
- 1.8 mg/kg
- Component total
- 1.8 mg/kg
- Evaporation residue
- 1.6 mg/kg
Usage
- Usage status
- Unknown
Indications & Contraindications
- Bathing indications
- Atopic dermatitis, Plaque psoriasis, Chronic eczema, Epidermal suppuration, Impaired glucose tolerance (diabetes), Cuts and grazes, Peripheral circulatory failure, Poor circulation, Depression, Xeroderma, Chronic pain or stiffness in muscles and joints (rheumatoid arthritis, osteoarthritis, lumbago, neuralgia, frozen shoulder, bruising, sprains and similar conditions in chronic phase), muscle stiffness due to motor paralysis, gastrointestinal dysfunction (gastric bloating, intestinal gas accumulation, etc.), high blood pressure (mild), dyslipidemia (mild), mild asthma or pulmonary emphysema, pain from hemorrhoids, autonomic instability, symptoms caused by stress (sleep disorders, etc.), convalescence after illness, fatigue recovery, health promotion, atopic dermatitis, psoriasis vulgaris, impaired glucose tolerance (diabetes), pustular infection of the epidermis, chronic eczema, cuts and grazes, peripheral circulatory failure, poor circulation, depression, xeroderma
- General indications
- High blood pressure (mild), Rheumatoid arthritis, Autonomic instability, Insomnia, Chronic pain or stiffness in muscles and joints, Muscle stiffness due to motor paralysis, Gastrointestinal dysfunction
- Contraindications
- Acute illness (especially with fever), Active tuberculosis, Malignant tumors, Severe heart disease, Respiratory failure, Renal failure, Bleeding disorders, Severe anemia, Any actively progressing illness, Pregnancy (especially early and late stages), Severe chronic dermatitis (sulphur springs), Sensitive skin or mucous membranes, eye conditions (acidic springs), Active phase of illness (especially with fever), active tuberculosis, advanced malignancy or severe general debility such as severe anemia, severe heart or lung disease causing shortness of breath with slight exertion, severe kidney disease with edema, gastrointestinal hemorrhage, visible bleeding, acute exacerbation of chronic illness, hypersensitivity of skin or mucous membranes, xeroderma in elderly persons
Drinking
- Drinkability
- Not drinkable
